The invention relates to a monitoring means and method for batteries contained within implantable devices for a human.
Implantable devices, such as heart pacemakers, drug dispensing apparatus, and the like, are utilized to provide life-sustaining functions at appropriate locations within a user. These devices typically utilize an implantable battery as a power means. Although these batteries have long life, they do periodically need replacing or recharging. Since the life of a user frequently depends upon the battery providing adequate power to his implanted device, it is essential that the battery does not fail during use. For example, in conventional pacemakers, periodic battery replacements or recharges are conducted. These replacements sometimes require surgical operations to remove the pacemaker, and are sometimes more frequent than necessary in order to insure a replacement prior to battery failure. In some conventional pacemakers, a slowing down of the heartbeat is relied on as a warning to a user that battery failure is eminent. However, such a slowing is not sensually perceptible at any one time, but rather results in a general tiredness or the like. There has long been a need for a battery monitor which will immediately alert a user that this battery needs replacing or recharging without his having to go to a doctor's office for a test. The invention solves the above problem by providing the user with a positive, easily identifiable alarm signal whenever his battery needs replacement or recharging.